Profiling tracer



A ril 2; 1935. R. D. SHAW 1,996,438.

PROFILING TRACER- Filed March 28, 1934 '2 Sheets-Sheet 1 INVENTOR R 0. Shaw ATTORNEY A ril 2, 1935. R. D. SHAW 1,996,438

PROFILING TRACER Filed March 23, 1934 2 Sheets-She t 2 i'kinn INVENTOR TTORNEY Patented Apr. 2, 1935 UNITED smras PATE MAW

T OFFICE PROFILING TRACER Application March 28 1934, Serial No. 717,760 9 Claims. (01. 9042) This invention relates to tracers for electrically controlled machine tools such as automatic die sinking machines shown and described in patent to J. C. Shaw 1,683,581 but more particularly the invention relates to an improvement in the tracer used in such machines when effecting contouring or profiling operations.

An object of the present invention is to provide animproved form of template following 10 tracer wherein the periphery of a generally circular template may be completely traversed automatically by the tracer and a work piece correspondingly profiled by a cutting tool, the relative movements of the cutter and work piece being controlled by contact between said tracer and template.

More particularly it is an object of the invention to provide means for constantly urging a contouring tracer as shown and described in patent to Shaw et al. 1.840,853 to contact with and constantly follow the periphery of a template.

A feature which enables me to accomplish the above named objects is that means are constantly acting upon the tracer to urge it directly toward the template and as the machine is operated these means acting to successively advance the tracer and cutter respectively about the template and work piece so that the tracer is simultaneously urged forwardly along the periphery of the template and'is constantly forced toward and into contact with the template.

Another feature whichis advantageous is that the template engaging end of the tracer is provided with a fixed sleeve or housing in which is rotatably mounted an annular plate or ring, there being a radially disposed slot in this ring engaged by a pin centrally located with respect to the template. Another feature is that springs are employed disposed between the rotatable plate or ring and the template engaging end of the tracer, one spring constantly urging the tracer toward the template and the other spring constantly forcing. the tracer forwardly in its direction of movement about the periphery of the template. I

With the above and other objects in view, my invention includes the features of construc- 50 tion and operation set forth in the following specification and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of this specification, I

5 ,have shown my invention incorporated as an rotatable ring whichvmembers in the patented attachment to the contouring tracer shown and described in the above mentioned Patent 1,840; 853 but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or lim- 5 iting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a central sectional view taken longitudinally through the entire tracer lever and cooperating parts and showing the present improvements applied thereto, the springs being indicated in diametrically opposite positions to more clearly indicate their construction;

Fig. 2 is a front or face view of the tracer showing the rotatable plate or ring member mounted with respect to a template being followed by the tracer; and

Fig. 3 is a diagrammatic view of a template, the periphery of which is being traced by the present form of tracer, the positions of the tracer and the rotatable ring being indicated in two difierent positions during operation.

In the above mentioned drawings I have shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from .the spirit of the invention.

Briefly and in its preferred aspect my invention may include the following principal parts: first, a tracer lever and support similar in everyway to those shown in the above mentioned Patent 1,840,853, the tracer lever being mounted for universal oscillatory movement about an intermedi ate point and in various operative positions opening and closing spaced contacts at the rear end thereof; second, a fixed casing or sleeve enclosing the tracer lever adjacent its template engaging end; third, a rotatable plate or ring supported for free rotation about an axis substantially concentric with the tracer lever; and fourth, springs attached to the lever and ring and disposed at an angle to each other.

As the contacts opened and closed by this tracer lever are in every way similar to those opened and closed in the above cited patent and control operation of the machine in the same manner,.itis not thought that further description or these parts is necessary. It will be noted, however, that there is no spring attached to the rear end of the tracer, nor is there a manually construction force the tracer toward an oscilthe radially acting resilient member or spring lated position. must be adjusted. This is done in the above At the front or template engaging end of the cited patent by periodically manually adjusting tracer lever I is mounted contact button II, the the ring to which the outer end of the spring diameter of which is chosen with respect to the at the back of the tracer is attached. The trace; diameter of the particular milling cutter emis thus at all times resiliently forced towards the ployed in cutting the work piece (not shown). periphery of the template. For this purpose the This button or contact point I I is, as shown, plate to which the spring is attached is succesmounted at the extreme forward end of the sively moved to four or more positions at aptracer l0, there being interposed between this proximately 90 apart. In the present construccontacting button and the contact lever two spirtion, however, the connection between the plate ally wound springs I2 and I3, each of which is or ring 16 and the template A due to the stud attached to a ring l4 loosely surrounding a por- 20 on thetemplateand radial slot I9 in the ring tion of the tracer lever in. The outer ends of IS constantly forces the ring 16 to assume sucthese springs l2 and I3 are individually attached cessive rotative positions and therefore the radial to radially extending screws [5 adjustably main spring or resiliently acting member i2 conthreaded within a ring [6. This ring l6, as shown stantly acts in a direction so that it urges the clearlyin Fig. 1, is supported for free rotation tracer I0 toward the periphery of the template upon the outer end of a sleeve ll fixed upon the A in all positions during the following of the comsupport l8 for the tracer lever and concentric plete template. Simultaneously the'supplementhereto. From the above description it will be tal spring l3 acts to force the tracer l0 forwardly seen that the plate or ring I6 is free to'rotate along the periphery of the template A. to any rotative position about the end of the It will be understood that the present consleeve I! while maintained concentric to the censtruction is not adapted'for all possible forms of tral position of the lever I0 and in accordance templates. Templates having reentrant steep with the positions of the springs l2 and I3 the angles would not be automatically traversed in tracer lever I0 may be urged in any direction. their entirety throughout their peripheries. A Radially disposed within the plate or ring l6 wide 'variety of templates, however, generally is a groove l9 which is disposed parallelly with circular in form may be entirely automatically the direction of one of the springs l2 or l3 beoperated on by the present means. tween the plate 16 and tracer 10. This groove What I claim is: i9 in operation is engaged by a stud or button 1. Atemplate following tracer for profiling ma- 20 outstanding from the template A being traced chines comprising in combination, a universally by the tracer lever ID. This stud 20, as shown is oscillatory tracer, lever, oscillation of which conpreferably moimted substantially centrally of trols relative movement between a cutter and the template A. The second or supplemental work, a member surrounding the template end of spring 13 is adjustably positioned at an acute the tracer lever and rotatable about a fixed axis, angle ive t the first sp in I w i is p said member having a radially disposed slot, a allel to the groove IS. The outer end of this projection disposed centrally of the template bespring l3 has its adjusting screw l5 mounted in ing traced and engaging within said slot, and rea small block 2| which may be positioned and silient means disposed between the tracer lever clamped to the r n r plate i at any desired and rotatable member normally holding said angle to the first spring l2. Preferably and as tracer against said template. Shown in the pp a p g I 3 is 2. Atemplate following tracer for profiling madiSDOSed t an angle of about 50 or 60 from the chines comprising in combination, a universally main Spring This Spring l3 S ay oscillatory tracer lever, oscillation or which conbe n either i Of the ma n pri l2 d pen trols relative movementfibetween a cutter and in up n he di c ion of v m n of the tracer work, a member adjacent the template end of the l 0 about the pl A- tracer lever and rotatable about a fixed axis, inter- In p a i t machine is started wit thee .connectingmeans between said rotatable member w tracer in engaging any point in the periphery of and template to vary the rotative position of the gtheftemplate A and with the cutter engaging a member during operation, and resilient means orre p n n Point Of the W Dieee (not disposed between the rotatable member and tracer w As the operation f cutting continues normally holding said tracer against said temand while the tracer I0 is traversing portions of at in ,1 positions the p p y 0f the template A the Plate r n 3. A template following tracer for profiling ma- -|6 is forced to rotate about the sleeve l1 and hine comprising in combination, a universally tracer lever it due to the contact between the oscillatory t r l oin t n of which tud Z0 0 butt 011 the mp A a the trols relative movement between a cutter and radial slot I9 in the ring I At a l ti ework, a member adjacent the template and rotat- I th a Spring isgpesitioned ahgulaily able about a fixed axis, interconnecting means in a Plan p a e to the plane of the template between said member and tracer lever to rotate $0 as to felee the Contact button ll directly said member as the tracer traverses the template, ain t h p iph of the template and resilient means normally holding said tracer thermore, the supp sp 3 p d against said template in all positions of the tracer at an angle to the main spring I2 is constantly relative to the template, said resilient means being urging the tracer in a direction about the temattached to and rotatable with said rotatable plate. member.

In the above mentioned Patent 1,848,503 the 4., Atemplate following tracer for profiling matracer follows the contour of the template in chines comprising in combination, a universally the same manner as de b d a v for a q oscillatory tracer lever, oscillation of which con rant f n nly 0! its pl Periph rytrols relative movement between a cutter and At successive positions of the tracer on the pework, a member adjacent the template end of the riphery oi the template the angular position of tracer lever and rotatable about a fixed axis tween said rotatable member and tracer lever nor-- mally holding said tracer against said template.

5. A template following tracer for profiling machines comprising in combination, a universally oscillatory tracer lever, oscillation of which controls relative movement between a cutter and work, a member adjacent the template end of the tracer lever and rotatable about a fixed axis, said member having a radially disposed slot, a projection disposed centrally of the template and engaging within said slot, and two angularly spaced resilient means disposed between the tracer lever and member normally holding said tracer against said template in all positions during operation.

6. A template following tracer for profiling'machines comprising in combination, a universally oscillatory tracer lever, oscillation of which controls relative movement between a cutter and work, a member adjacent the template end of the tracer lever and rotatable about a fixed axis, said member having a radially disposed slot, a projection disposed centrally of the template and engaging within said slot, a spring attached at one end to said rotatable member and extending parallelly to the slot therein, the other end engaging the tracer lever whereby said tracer lever is held in contact with the template, and a supplemental spring disposed between the tracer lever and said rotatable member at an angle to said first spring.

'7. A template following tracer for profiling machines comprising in combination, a universally oscillatory tracer'lever, oscillation of which controls relative movement between a cutter and work, a member adjacent the template end of said lever and rotatable about a fixed axis concentric to said tracer lever, springs attached at one end to spaced positions on said rotatable member and at their other ends engaging the tracer lever whereby said tracer lever is held in contact with the template, and means to rotate said member as the tracer traverses the periphery of the template.

8. A template following tracer for profiling machines comprising in combination, a universally oscillatory tracer lever, oscillation of which controls relative movement between a cutter and work, a member mounted on said lever and rotatable about a fixed axis substantially concentric with said lever, interconnecting means between said member and lever to rotate said member during operation as the tracer traverses the template, and resilient means normally holding said tracer against said template in all positions of the tracer relative to the template, said resilient means being attached to and. rotatable with said rotatable member.

9. A template following tracer for profiling machines comprising in combination, a universally oscillatory tracer lever, oscillation of which controls relative movement between a cutter and work, a member mounted on said lever and rotatable about a fixed axis, springs attached at one of their ends to spaced positions on said rotatable member and at their other ends engaging the tracer lever whereby said tracer lever is held in contact with the template during operation, and means to rotate said member as the tracer arm traverses the periphery of the template.

ROBERT D. SHAW. 

